Asencio, 30, is 4-0 with an International League-leading 20 saves (in 25 chances) and a 2.15 ERA in 34 appearances with Norfolk this season. He was named an International League All-Star and has struck out 41, walked seven and recorded 27 scoreless appearances.

He made his Major League season debut in Friday's 8-5 win over the Blue Jays, pitching a scoreless seventh inning with two strikeouts. He allowed a leadoff walk and a one-out single but struck out Jose Bautista and Edwin Encarnacion, both swinging, to end the inning.

"Asencio has been pitching well all year down there, wanted to get a look at him and get a feel for what we have down there before the end of the month," manager Buck Showalter said, referring to the July 31 non-waiver Trade Deadline. "There's something we are going to need there that you can't provide from within."

Showalter also said the club wanted to keep Stinson -- who was recalled prior to Wednesday's game -- on a semi-regular pitching schedule. The right-hander last started for Norfolk on Saturday, and got the ball in Friday night's game. He allowed one run in five innings with five strikeouts to earn the win in the Tides' 4-1 win over Charlotte.

"He's coming off two or three really good starts, and we don't want him waiting for someone to fail before he comes in and pitches," Showalter said. "There was a bullpen game going on [Friday for Norfolk], just thought it'd be good for him."

The Asencio addition gives the Orioles another right-handed power arm, something that has been missing since they traded Pedro Strop. Acquired in a March trade with Milwaukee, Asencio held Triple-A hitters to a .174 average this season, limiting left-handers to a .484 OPS and right-handers to a .569 OPS. His unintentional walk rate of 1.19 per nine innings is also top in the International League. In 39 career Major League appearances with the Braves, Indians and Cubs, Asencio has a 5.23 ERA.

To clear a 40-man roster spot for Asencio, the Orioles designated Jair Jurrjens for assignment.